Mobile track tamping machine



Feb. 14, 1961 F. PLASSER ETAL MOBILE TRACK TAMPING MACHINE Filed Sept.24, 1957 BY J MM.

Unite States Patent f'ice MOBILE TRACK TAMPING MACHINE Franz Plasser andJosef Theurer, both of Johannesgasse 3, Vienna, Austria Filed Sept. 24,1957, Ser. No. 685,863 Claims priority, application Austria Sept. 27,1956 3 Claims. (Cl. 104-12) The present invention relates to railroadballast tamping machines, and more particularly to a novel tamping toolarrangement for such machines.

Track tamping machines with pairs of laterally moving vibratory tampingtools are known. The ends of each pair of tools are lowered into theballast at each side of a tie and they are then moved together whilethey are vibrated to tamp the ballast underneath the tie. While theballast under the railroad ties may thus be satisfactorily tamped, theballast between the tamped ties remains loose and there remains thepossibility, therefore, for the tamped ballast to escape sideways intothe loose ballast, thus eventually loosening the entire ballast bed.

In accordance with this invention, at least one additional tamping toolis provided behind the tamping tools used for tamping ballast beneaththe ties to tamp the ballast between the adjacent ties. This makes itpossible to tamp the loose ballast between the ballast which has beentamped underneath the ties. Thus, the tamped ballast cone under the tiesreceives a lateral support of tamped ballast.

According to a preferred embodiment of the invention, the additionaltamping tool is a ballast vibrator with a working surface almost as wideas the distance between the ties.

While the pairs of vibratory tamping tools and the additional tamper maybe mounted on the machine'carriage independently, it is more economicaland preferred to mount them all on a common vertically adjustablecarrier. It is possible to make the additional tamper adjustable inheight independently from the vertical adjustment of the pairs oftamping tools and also to mount them laterally adjustably so that thespacing between the pairs of the tamping tools and the additional tampermay be varied at will and in accordance with the tie spacing so that thetamper may work always midway between two adjacent ties.

The invention is not limited to any specific type of vibratory tampingtools and the ballast surface tamper may be a vibrator which may bedriven mechanically, pneumatically, electrically or hydraulically.

If desired, the drive and control for the pairs of tamping tools and theadditional tamper may be the same since they are operatedsimultaneously. Such an arrangement makes the cost of the additionaltamper very small and the improved results obtained by such a tamper farexceed the small increase in cost.

The invention will be described in conjunction with a now preferredembodiment thereof which is illustrated in a schematic side view in thesingle figure of the accompanying drawing.

The illustrated track tamping machine is largely conventional and sinceits general structure is well known, the description will not beencumbered with details of the known structure. Merely by way of exampleand in no way limiting the invention to this specific machine, one typeof track tamper to which the present invention may be applied is themachinedescribed and claimed r 2,971,472 Patented Feb. 14 1961 lin ourcopending application Serial No. 462,086, filed October 13, 1954, nowPatent No. 2,876,709 dated March 10, 1959.

As shown, such known track tampers comprise a carriage 1 on which avertically movable tamping tool carrier 2 is mounted. The carrier isadapted to glide upward and downward on the columns 2a. A laterallyextending eccentric shaft 3 is mounted on carrier 2. A pair of tampingtools 4 is linked to the ends of arms 6 and when the eccentric shaft isrotated, the tamping tools will be vibrated. The lower jaws 5 of thetamping tools reach into the ballast and the tools are pivoted to thecarrier at 4a where a mechanism (not shown) is connected to move thetools towards and away from each other. Thus, when the tamping tools 4are vibrated and moved together, they tamp the ballast underneath thetie 8 where a dense ballast cone is formed.

Behind (in the direction of travel) the tamping tool pair, a bracket 11is provided on the carrier 2 to carry the additional tamper 10 whichcarries a surface vibrator 9. Vibrators of this type are also Well knownper se and the vibrator drive has, therefore, not been illustrated toavoid encumbering the drawing with structural details Well within theskill of the mechanic. If desired, there may be a common drive for thetamping tool pairs and the additional tamper.

While the tamping tool ends 5 tamp the ballast by their horizontalmovement (and vibration), the additional tamper 9 works verticallydownward.

The machine operates as follows:

The machine is driven along the tracks 7 until it has reached a positionwhere the ececntric shaft 3 is located above the first tie to be tamped.The carrier 2 is then lowered so that the tamping tool ends 5 reach intothe ballast at both sides of the tie. In this position (as shown), theadditional tamper 9 contacts the ballast between two ties which haveboth been tamped in the preceding working step. The common drive for thetamping tools is now actuated and while the pairs of tamping tools tampthe ballast under tie S, the tamper 9 tamps the ballast between the twonext following ties. At the end of the operation, the entire ballastunderneath as well as between the ties will be of homogeneous density.

It is obvious that the invention is not limited to the illustratedtamper and it is also immaterial where the additional tamper is locatedas long as it is mounted behind the pair of tamping tools and so that itcan tamp down ballast between adjacent ties. Numerous variations andmodifications of the illustrated embodiment may occur to the skilled inthe art without departing from the spirit and scope of the invention asdefined in the appended claims.

What we claim is:

1. In combination with a track tamping machine having a verticallyadjustable tamping tool carrier mounting a pair of laterally movabletamping tools laterally adjacent each track rail for tamping ballastunder a tie: at least one vertically downwardly working tamperassociated with each tamping tool pair and mounted on the machine behindthe tamping tool pair and at such a distance therefrom that it isadapted to tamp the ballast between two successive ties previouslytamped by the tamping tool pair.

2. The combination of claim 1, wherein the vertically downwardly workingtamper comprises a surface vibrator having a working face of smallerWidth than the distance between adjacent ties.

3. The combination of claim 1, wherein the pairs of tamping tools andthe additional tamper are both mounted onthe vertically adjustablecarrier.

(References on following page) References Cited in the file of thispatent Zurmuhle J uly 5, 1 955 5 FOREIGN PATENTS France Mar. 31, 1954France Apr. 20, 1955 Germany June 1, 1926

